The present invention relates to a valve arrangement of the type including an operating valve arrangement provided in the form of a relay valve and a control valve arrangement, used, for example, for regulating supply of a pressure medium in a vehicle braking system equipped with an anti-lock braking (ABS) system.
A valve arrangement of this type, which consists generally of a relay valve and a control valve arrangement, is known, for example, from the valve design embodied as instrument number 472 500 100 0 of the company WABCO GmbH. Such valve arrangement can be used with a vehicle braking system equipped with an anti-lock braking (ABS) system. Insofar as the control valve arrangement is actuated by the ABS electronic system, use of this valve arrangement permits the brake cylinders of the vehicle brake system to be aerated or vented independently of the pressure controlled by the motor vehicle brake valve. When in a passive state, the valve arrangement functions as a relay valve used for rapid aeration and venting of the brake cylinders.
In the aforementioned valve arrangements, it is advantageous for the relay valve and the control valve arrangement to be mounted as close together as possible in order to keep the paths of the pressure medium as short as possible. This has been accomplished, for example, by attaching the relay valve and the control valve arrangement on a common support, or connecting them to each other by means of bridging elements. The pressure medium connections between the relay valve and the control valve arrangement are then established by means of pressure medium lines that are advantageously as short as possible.
It is the object of the present invention to provide a valve arrangement of the type mentioned above in which placement of the valves of the valve arrangement relative to each other and the nature of pressure medium connections of the valve arrangement can be improved.
In accordance with these and other objects of the invention, there is provided a valve arrangement which includes an operating valve and a control valve arrangement. The operating valve includes a housing defining a pressure medium input chamber, a pressure medium output chamber and a pressure medium outlet leading to a pressure medium sink. The operating valve also includes an inlet and outlet valve arrangement via which the pressure medium output chamber may be selectively connected to the pressure medium input chamber or to the pressure medium outlet, or can be closed off from both. The control valve arrangement is installed directly on the housing or in a recess formed in the housing of the operating valve arrangement, and includes a pressure medium input chamber, a pressure medium output chamber and a pressure medium outlet. The control valve arrangement further includes a controlled valve arrangement via which the pressure medium output chamber can be selectively connected to the pressure medium input chamber or to the pressure medium outlet of the control valve arrangement. The pressure medium outlet of the control valve arrangement is connected to the pressure medium outlet of the operating valve arrangement. The operating valve arrangement and the control valve arrangement are advantageously designed and connected to each other in such manner that at least a portion of the control valve arrangement is located in, or constituted by, the operating valve arrangement.
The invention offers, in particular, the advantage of maintaining a valve arrangement comprising an operating valve arrangement and a control valve arrangement combined into one compact component of simple structure.
By combining the operating valve arrangement and the control valve arrangement into one compact component, the paths of the pressure medium are shortened, such that a better response behavior of the valve arrangement is achieved. In addition, such design obviates the use of bridging elements and reduces the expense otherwise required for external pressure medium lines and screw connections.
By connecting the pressure medium outlet of the control valve arrangement to the pressure medium outlet of the operating valve arrangement, only one noise suppressor is required for proper function.
According to a further embodiment of the invention, part of the control valve arrangement is located in, or constituted by part of, the operating valve arrangement.
According to advantageous further developments of the invention, a valve seat or a receptacle for the valve seat of a solenoid valve of the control valve arrangement is installed in or at the operating valve arrangement, or is formed by part of the operating valve arrangement. The seat of the a control piston of the control valve arrangement is formed by facing sides of an area portion of the operating valve arrangement and an area portion of the control valve arrangement.
By virtue of the above-mentioned measures, the invention provides the advantage that the controllable valve arrangement of the control valve arrangement and the solenoid valves can be assembled and disassembled easily. Due to the fact that the above-mentioned valves and the control piston are located in areas of the operating valve arrangement and of the control valve arrangement which border each other, repair work or the replacement of components merely requires that the housing of the control valve arrangement be removed from the housing of the operating valve arrangement.
In accordance with an advantageous embodiment of the invention, the control valve arrangement is located laterally on the upper part of the housing of the operating valve arrangement. This arrangement has the advantage that the electrical system which serves to process electrical signals and to actuate the valve arrangement electrically can also be mounted on the valve arrangement.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.